Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations are absent, so the description carries the full burden. It discloses that results come from live inventory and include a customer yen price plus public URL, which is genuine behavioral context, but says nothing about result volume, pagination, rate limits, or whether it is strictly read-only.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with no filler, front-loading what the tool searches over before stating the return values. Efficient, though slightly light on structure for eight parameters.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, stating the returned fields (yen price, public URL) is necessary and is done. No annotations exist and the parameter coverage gap is the main omission, but for a read-only search the description is close to complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 38%, so several of the eight parameters (minYear, maxYear, minMileageKm, maxMileageKm) are undocumented in both the schema and the description. The listed body types loosely echo the category enum, but no filter syntax, units, or defaults are added beyond what the schema already states.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (search) and a clearly bounded resource (live Japan Direct Trucks inventory), and enumerates the covered body types. It contrasts reasonably with get_vehicle by framing itself as a search over live inventory, though it never names a sibling explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies a browse/filter use case by calling the inventory 'live', which suggests freshness-based selection, but it gives no when-to-use guidance, no exclusions, and never says when to prefer get_vehicle for a specific listing instead.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.